diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s
index 8e05acf..1b28098 100644
--- a/src/runtime/sys_linux_386.s
+++ b/src/runtime/sys_linux_386.s
@@ -233,9 +233,9 @@
 	MOVL	g_m(AX), SI // SI unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVL	0(SP), DX
-	MOVL	DX, m_vdsoPC(SI)
-	LEAL	sec+0(SP), DX
+	LEAL	sec+0(FP), DX
+	MOVL	-4(DX), CX
+	MOVL	CX, m_vdsoPC(SI)
 	MOVL	DX, m_vdsoSP(SI)
 
 	CMPL	AX, m_curg(SI)	// Only switch if on curg.
@@ -296,9 +296,9 @@
 	MOVL	g_m(AX), SI // SI unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVL	0(SP), DX
-	MOVL	DX, m_vdsoPC(SI)
-	LEAL	ret+0(SP), DX
+	LEAL	ret+0(FP), DX
+	MOVL	-4(DX), CX
+	MOVL	CX, m_vdsoPC(SI)
 	MOVL	DX, m_vdsoSP(SI)
 
 	CMPL	AX, m_curg(SI)	// Only switch if on curg.
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index 9493101..58d3bc5 100644
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -221,9 +221,9 @@
 	MOVQ	g_m(AX), BX // BX unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVQ	0(SP), DX
-	MOVQ	DX, m_vdsoPC(BX)
-	LEAQ	sec+0(SP), DX
+	LEAQ	sec+0(FP), DX
+	MOVQ	-8(DX), CX
+	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	DX, m_vdsoSP(BX)
 
 	CMPQ	AX, m_curg(BX)	// Only switch if on curg.
@@ -275,9 +275,9 @@
 	MOVQ	g_m(AX), BX // BX unchanged by C code.
 
 	// Set vdsoPC and vdsoSP for SIGPROF traceback.
-	MOVQ	0(SP), DX
-	MOVQ	DX, m_vdsoPC(BX)
-	LEAQ	ret+0(SP), DX
+	LEAQ	ret+0(FP), DX
+	MOVQ	-8(DX), CX
+	MOVQ	CX, m_vdsoPC(BX)
 	MOVQ	DX, m_vdsoSP(BX)
 
 	CMPQ	AX, m_curg(BX)	// Only switch if on curg.